Sudan's defence minister on Tuesday called for a delay to a secession referendum in the oil-producing south until border and security issues could be resolved.
The call from Abdel Rahim Mohamed Hussein, the first from a senior member of north Sudan's dominant National Congress Party, is certain to anger southerners, who have until now refused to budge from the planned date of Jan. 9.
Asked if the referendum should be delayed, Hussein told reporters in Cairo: "According to the reality on the ground, yes. Border issues and Abyei must be resolved within the framework of one nation ...
"What is important is security and stability of citizens. Everything must be sacrificed to ensure there is security and stability before the referendum takes place."
The plan for a vote was set out in a 2005 peace deal that ended decades of north-south civil war.
Preparations have fallen far behind schedule and northerners and southerners remain at loggerheads over a series of key issues, including the course of their shared border.
The two sides have accused each other of building up troops near border areas, and diplomats say there is a risk that fighting could erupt.
Residents of the disputed oil-producing Abyei area in central Sudan have been promised a vote, also scheduled for Jan. 9, on whether to join north or south Sudan.
Northern and southern leaders disagree about who should take part in the vote and leading northern politicians have already said it will be impossible to run the Abyei plebiscite on time.